A reaction between benzene and propylene gives cumene. Oxidation of cumene results in cumene hydroperoxide. The cumene hydroperoxide is acid decomposed into phenol and acetone. A combination of these known reactions is the cumene process which is currently a mainstream process for the production of phenol.
The cumene process gives acetone as a by-product, and is valuable when both phenol and acetone are required. However, if the acetone produced is in excess of demand, the economic efficiency is deteriorated due to the price difference between acetone and starting material propylene. Methods have been then proposed in which by-product acetone is reused as a material in the cumene process through various reactions.
Acetone is readily hydrogenated to isopropanol. Patent Document 1 discloses a process in which the isopropanol thus obtained is dehydrated to propylene and the propylene is reacted with benzene to give cumene, in detail acetone is reused as a material in the cumene process by being converted to propylene through two reaction steps.
In the reuse of acetone, an industrial and practical process should be established which is capable of producing propylene from acetone with high selectivity. Further, the establishment of industrial and practical processes capable of producing not only propylene but other olefins from general ketones with high selectivity is also valuable in other various processes.
Patent Document 2 discloses a process in which propylene is obtained through hydrogenation of acetone at 400° C. in the presence of a catalyst containing Cu (25%), zinc monoxide (35%) and aluminum monoxide (40%). In spite of the high reaction temperature of 400° C., however, the acetone conversion is low at 89%. Further, the propylene selectivity according to this document is only 89% because of a side reaction hydrogenating propylene to propane.